Logic problem question?

Question

If 513 people watch a magician and one third of them guessed how he did the trick, how many did not know?

Answer 1

It’s not a logic problem; it’s a silly example where ‘logic’ masquerades as pedantry that disregards normal semantics. In normal conversation, the question is unambiguous and communicates that 1/3 figured it out and the rest didn’t (think about it – we all use the term ‘you guessed it’ or ‘someone guessed how he did it’ to informally convey the point that they got it right; plus, in normal convo, the implication that the rest didn’t get it is well-understood). But our silly logic test can delude us into thinking that if we parse the sentence in a rigid and almost legalistic fashion, we can argue otherwise – e.g. the ‘facts’ are that 513 watched and 1/3 of them hazarded a guess; nothing is explicitly said about who knew and who didn’t know how he did the trick (it doesn't say if any or all of the 1/3 got it right, if the remaining 2/3 had some or all who knew but didn't speak up, etc. -- therefore, we can NOT say anything about how many did not know). Again, the irony for me is that this may seem to be 'logic' in logic puzzles and convince people that they think logically but it’s gross illogic and sillyness to me, given what I said in the beginning.

Answer 2

513

Answer 3

513

Answer 4

i can't tell based on the information given. anywhere from 342 to 513 people, depending on how bad the magician was and how good the person was at guessing.

Answer 5

513 1/3 guessed but none knew

Answer 6

A guess is still not knowing? 513

Answer 7

513/3=171
171X2=342 did not know
But 171 GUESSED IT, so you have to evaluate the probabilities of those whom guessed it right amongs the 171 persons...Then you have to find out how many knew the trick amongs the 342 persons.
It is unscientific to assume they knew...Sorry!

Answer 8

It's not a logic problem because you failed to specify how many of them already knew how to do the trick before the magician performed it.

But, assuming none of them knew how to do the trick before the magician performed it, and assuming none of the people who guessed how he did the trick guessed correctly, then none of them knew.

But some of them may have guessed correctly, so the correct answer cannot be determined given the information you have supplied.

Answer 9

We know that 171 people "guessed" so they did not know for sure.

The rest didn't give an answer, so we do not know if they knew or not.

So: 171 people did not know the answer as they guessed. The rest we do not know as not enough info was given. The only one we know for sure knew the trick was the magician. Why am I still answering this question??

Answer 10

If 1/3 guessed how the trick was done, it doesnt mean the rest didn't know. They might have known but not guessed out loud. But again, did the 1/3 guess out loud? Did the 2/3 guess out loud and not have the right answer?